Thermostat control for flatirons and the like



Oct. 22, 1957 A. e. SWENSON 2,810,812

THERMOSTAT CONTROL FOR FLATIRONS AND THE LIKE Filed June 7. 1955 United States Patent THERMOSTAT CONTROL FOR FLATIRONS AND THE LIKE Alfred G. Swenson, Ontario, Califi, assignor to General Electric Company, a corporation of New York Application June 7, 1955, Serial No. 513,676

7 Claims. (Cl. 219-45) My invention relates to flatirons, and more particularly, to thermostats for flatirons and the like.

Flatirons are, of course, normally employed for ironing a wide variety of fabrics which, for most effective ironing, require widely varying temperature settings. It is therefore conventional to provide some means accessible to the user whereby the temperature setting of the iron may be readily changed as different materials are encountered. The thermostat, of course, must normally be arranged in heat transfer relationship with the soleplate so as to respond very closely to the temperature of the soleplate. On the other hand, the control for most effective use, must be providedsomewhere on the upper portion of the iron. It is, therefore, necessary to extend a control member in some manner from the soleplate upwardly through the cover and possibly also the handle to a point accessible to the user. Despite reasonably careful usage, there is always the possibility that the iron will be dropped, for example, by accidentally falling or being pulled from the ironing board, resulting in a severe jar to the iron and its associated thermostatic control. Also,

ecause of the relatively high temperatures at which the iron may be operated, the soleplate, the cover and the handle may shift relative to each other as a result of the differential expansion of the different materials employed for these parts. For these reasons an element extending between and to some extent through these members is subject to being distorted or shifted with resultant adverse effect on the control. In accordance with my invention, a structure is provided between the exterior control knob and the interiorly mounted thermostat by which the danger of adverse effect on the control through the drop ping of the iron or the aforementioned differential expansion is minimized. In addition, in accordance with my invention, a greatly simplified structure, lower in cost and sturdy in construction, is provided for controlling the thermostat. Also I have provided a structure in which at least one element thereof is arranged to serve multiple functions, resulting in lower cost.

It is an object of my invention to provide an improved thermostatic control arrangement for fiatirons and the like.

It is another object of my invention to provide such a control constructed so as to minimize any adverse effect thereon resulting, for example, from differential expansion of the various parts employed in the iron structure, or resulting from dropping or otherwise jarring the iron.

It is a further object of my invention to provide a control structure for adjusting the thermostat setting of a ffatiron and the like which is simply constructed and assembled and which is lower in cost yet sturdy and dependable in structure.

It is still another object of my invention to provide a combined structure for mounting the thermostat itself and the control therefor.

In carrying out the objects of my invention in one form thereof, a stud is secured to the soleplate and extends up- Patented Oct. 22, 1957 wardly through an opening in the cover which is of sufficiently greater size than the cross-section of the stud to provide freedom of motion between the cover and the stud. A unitary structure, including an upwardly extending leg and a lower cam is mounted on the stud. A control knob positioned exteriorly on the body of the iron is mounted on the stud and engages the upwardly extending leg to effect change of the thermostat setting. Elements of the integral structure may also be provided to engage the stud at any intermediate position to lend further stability to the assembly. Finally, the stud serves not only for supporting the unitary control structure but also for mounting the thermostat itself.

Further objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

For better understanding of my invention, reference may be had to the accompaniyng drawing in which Fig. 1 is a sectional elevation view of a portion of a fiatiron illustrating an embodiment of my invention.

Fig. 2 is an exploded view of portions of the control structure.

Referring to the drawing, there is shown a flatiron.

which includes a soleplate, a cover and a handle, portions of which are shown at 1, 2 and 3 respectively. In the form illustrated, a steam iron has been shown which includes a reservoir 4, but it will be apparent that my invention is equally applicable to a dry flatiron.

In order to control the temperature of the soleplate so as to provide suitable temperatures for ironing different materials, a thermostat, generally indicated by 5, is mounted on the soleplate. This thermostat may be of any suitable type, for example, including a fixed contact 6 and a movable contact 7. By way of example, the thermostat may be of the general structure shown in Patent 2,681,521, Finlayson et 211., issued June 22, 1954, and assigned to the assignee of the present invention. Such a thermostat includes a relatively stiff arm 8 upon which the movable contact 7 is mounted and a flexible arm 9 mounted on an insulator 10 for supporting the arm 8. An insulator 11 is mounted at the junction of the arms 8 and 9. The thermostat includes a frame member shown generally at 12. In order to effect opening and closing of the contacts 6 and 7 for controlling the energization of the flatiron, a bimetallic strip 13 is mounted in heat transfer relationship with the soleplatev 1. An insulator 14 is mounted at the free end of the and disengagement of the contacts 6 and 7.

Since a wide variety of materials are usually ironed and since these materials require a wide variety of temperature settings for most effective ironing, it is usual to provide some readily accessible member whereby the user can adjust the temperature setting of the iron. In accordance with my invention, a simple, low-cost, sturdy structure is provided for this purpose. This structure includes a stud 15 which is secured in any suitable manner to the soleplate 1, for example, by being screw-threaded into a recess in the soleplate. This stud 15 extends ver tically upward from the soleplate and passes through an opening 16 in the cover 2 and extends upwardly beyond this opening. The stud facilitates mounting of the thermostat including the bimetal in engagement with the soleplate. Specifically, this is accomplished by an upset shoulder 17 above the screw-threaded lower portion 17a of the stud 15; this shoulder 17 engages the frame 12 and holds the frame 12 and the bimetal strip 13 firmly against the soleplate 1.

In addition to providing means for mounting the thermostat on the soleplate, the stud also functions for mounting the cover 2. Thus, the upper'end of the stud -is also screw-threaded, as indicated at 18, and a nut 19 is provided in screw threaded engagement with this portion 18 and engages the top of the cover 2 to mount the cover and complete the body of the iron.

Finally, the stud 15 further functions to support the control structure by which the temperature setting ofthe thermostat is adjusted. For this'purpose a control member 20 is rotatably mounted on the stud 15. In'the form illustrated, this control member 20 comprises a'unitary structure which includes a lower horizontal ieg 21, which bears against the shoulder 17, and'a vertical leg or control shaft 22, which extends upwardly from the leg 21 generally parallel to the stud 15. The horizontalleg 21 is-formed to include a cam 23 for engaging the insulator 11 to adjust the temperaturesetting of the thermostat. For mounting the control member 20 on the stud, the le 21 isformed further to include a generally centrally located opening 24. It can be seen that the unitary cam and control shaft structure merely need be placed on the supporting stud 15, and noriveting or other fastening operations are involved.

The leg 22 extends'upwardly through an arcuate slot 25 provided in the cover 2. At an intermediate point along the leg-22, the control-member is formed to provide two parallel laterally extending'tongues 26. In thefor m illustrated, these tongues are formed conveniently as an integral part of the control member, but it will be apparent that they could, if desired, be formed as separate brackets mounted on the leg 22. The tongues 26 are spaced so as to engage opposite sides of the stud 15 for assisting in supporting the control member on the 'stud and minimizing any twisting or distortion of the control member during use.

At the upperend, the leg -22 is arranged to engage a control knob 27 which is accessible to the user abovethe body of the iron for adjusting-the temperature setting of the iron. In the specific form illustrated, the control knob 27 is formed to include an inverted cup-shaped member 28,.formed usually of plastic or other suitable poor heat-conducting material. T he control knob furtherincludes a secondmember 29 which is constructed in the form of a disc3tl having a-plu'rality of upwardly extending fingers 31. The fingers 31 are arranged to frictionally engage the inner-surface-ofthe cup-shaped member 23. In order to moreaccurately position the member'and to minimizeany possibility of slippage between the member 29 and the member 28, recesses may be provided on the interior surfaceof the cup-shaped member 28 for receiving'the' fingers 31. The member 29-is formed centrally to provide an upwardly extendingcircular flange portion 32 adapted'to rotate on the reduced diameter portion 32a of the stud 15 above the shoulder 32b. In order to provide positive'engagement between the control member 2t) andspecifically its upwardly extendingleg 22 and the member 29, the latter is further formed to include an opening 33 for receiving theupper end of the leg 22 in reasonably closeengagement. In order to minimize'heat transfer from the soleplate through the stud to the control knob 27, the member'29 is preferably made relatively thin and of a relatively poor heat-conducting material.

In order that the user may accurately determine'the temperature for whichithe iron is set, the control knob 27 is further formed to include an integral pointer 34 extending radially outwardat one point of the circumference'the'reof. In the conventional manner, a temperature-indicating plate shown generallyat 35 is provided so that the position. ofith'e pointer relative'to the plate indicates the temperature'setting. The plate may begraduated in degrees, or,'rnore.comn1only, may be marked with legends toindicate the particular materials which are most satisfactorily ironed at any particular setting of the control member.

The operation of the control structure will be clear from theforegoing description. If it is desired to change the temperature setting, the control knob 27 is rotated, carrying with it rotatably mounted control member 20 and thereby moving the cam 23 relative to the insulator 11. The insulator 11 is thereby raised or lowered, depending on the direction of movement of the control member. If it is desired to increase the temperature setting of the iron, the control knob 27 is rotated so as to raise the insulator 11 thereby moving the arm 8 upwardly relative to the insulator 14 of the 'bimetal 13. Accordingly,'the bimetal 13, which in the form illustrated, bends upwardly as the temperature increases, must move a greater distance in order to efiect opening of the contacts 6 and 7 for de-energizing'the flatiron. The iron will, therefore, attain a higher temperature before the heating element thereof is de-energized. Conversely, if it is desired to change the iron to a lower temperature setting, the control knob is rotated so that the insulator 11 is shifted to a lower position.

It will be seen that a simple yet effective structure for controlling temperature settings has been provided. Further, it will be noted that the opening '16 in the cover has been made somewhat greater than the cross-section of the stud 15 so should dififerential'expansion of the various parts'occur or should the iron be dropped, causing a slight relative movement of the cover relative to the soleplate and hencerelative to the stud, this movement of'the covendoes not 'cause engagement with the stud 15. Therefore, shifting or distortion of the stud 15 is avoided. Further, it can be seen that by my structure I havearrangedfor the single stud '15 to function not only for supporting the control member 20, but also for mounting the thermostat and the cover, thereby materially reducing the ,cost.

-While I have shown and described a specific embodiment of my invention, I do not desiremy invention to be limited to the particular construction shown and described and I intend bythe appended claims to cover all modifications Within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a fiatiron including a soleplate and a cover, a thermostat mounted on said soleplate in heat transfer relationship therewith for controlling the heating of said soleplate, a stud mounted on said soleplate and extending upwardly therefrom, said cover having an opening through which said stud extends, a control member for said thermostat rotatably mounted on said stud, said control member including a cam and a leg extending generally parallel to said stud and through said cover, a disc rotatably mounted on said stud and including an opening therein to receive said upwardly extending leg for rotating said cam, said disc including upwardly extendingjfin'g'ers, and a knob of invertedcup-shape engaged on the interior thereof by said extending fingers to connect said knob to said disc, said thermostat including a portion engaging said cam whereby rotation of said cam varies the temperature setting of said thermostat.

2. In a flatiron including a soleplate and a cover, a thermostat mounted on said soleplate in heat transfer relationship therewith for controllingthe'heating of said soleplate, a stud mounted on said soleplate and extending upwardly therefrom, said cover having an opening through which .said stud extends, a control member for said thermostat rotatably mounted on said stud, said con- 7 trol member including a cam and a leg extending generally parallel to said stud and through said cover, said leg of said control member including two parallel laterally extending tongues intermediate .its length, said tongues being disposed in engagement with opposite sides of said stud, and a rotatable knob mounted on said stud and engaging said leg for rotating said cam, Isaid thermostat including a portion engaging said cam whereby rotation of said cam varies the tempearture setting of said thermostat.

3. In a flatiron including a soleplate and a cover, a thermostat mounted on said soleplate in heat transfer relationship therewith for controlling the heating of said soleplate, a stud mounted on said soleplate and extending upwardly therefrom, said cover having an opening through which said stud extends, means on said stud engaging said cover for mounting said cover on said soleplate, a control member for said thermostat mounted on said stud, said control member including a cam at its lower end rotatably mounted on said stud and a leg extending upwardly therefrom generally parallel to said stud, said cover having a second opening therein, said leg extending through said second opening, ciated with said control member and bearing against said stud at a point intermediate the length of said stud, and a rotatable control knob mounted on said stud and engaging said leg for rotating said cam, said thermostat including a portion engaging said cam whereby rotation of said cam varies the temperature setting of said thermostat.

4. In a fiatiron including a soleplate and a cover, a thermostat mounted on said soleplate in heat transfer relationship therewith for controlling the heating of said soleplate, a stud mounted on said soleplate and extending upwardly therefrom, said cover having an opening through which said stud extends, means on said stud engaging said cover for mounting said cover on said soleplate, a unitary control member for said thermostat rotatably mounted on said stud, said control member including a horizontal leg and a vertical leg, said horizontal leg including a cam and a central opening therein for receiving said stud, said cover having an arcuate slot therein, said vertical leg extending through said arcuate slot in said cover, means associated with said control member and bearing against said stud at a point intermediate the length of said stud, and a rotatable control knob mounted on said stud and engaging said vertical leg for rotating said cam, said thermostat including a portion engaging said cam whereby rotation of said cam varies the temperature setting of said thermostat.

5. In a fiatiron including a soleplate and a cover, a thermostat including a temperature sensing device and a switch assembly actuated thereby for governing the temperature of said soleplate, a stud mounted on said soleplate and extending upwardly therefrom, said cover having an opening therein through which said stud extends, means on said stud for securing said temperature sensing device and said switch assembly in heat transfer relationship with said soleplate, means cooperating with said stud for mounting said cover on said soleplate, a control member for said thermostat rotatably mounted on said stud, said control member including a cam and a leg extending generally parallel to said stud and through said cover, and a control knob rotatably mounted on said stud and engaging said leg for rotating said cam, said thermostat including a portion engaging said cam whereby rotation of said cam varies the temperature setting of thermostat.

6. In a flatiron including a soleplate and a cover, a thermostat for governing the temperature of said soleplate, a stud mounted on said soleplate and extending upwardly therefrom, said cover having an opening therein through which said stud extends, means on said stud for mounting said thermostat in heat transfer relationship with said soleplate, means cooperating wtih said stud for mounting said cover on said soleplate, a control member for said thermostat rotatably mounted on said stud, control member including a cam and a leg extending generally parallel to said stud and through said cover, parallel laterally extending tongues projecting from said control member intermediate its length, said tongues being disposed in engagement with opposite sides of said stud at a point intermediate the length of said stud, and a control knob rotatably mounted on said stud and engaging said leg for rotating said cam, said thermostat including a portion engaging said cam whereby rotation of said cam varies the temperature setting of said thermostat.

7. In a flatiron including a soleplate and a cover, a bimetallic temperature sensing device, a switch assembly including a switch adapted to be actuated by said temperature sensing device, a stud mounted on said soleplate extending upwardly therefrom and including means for securing said temperature sensing device and said switch assembly to said soleplate, said cover having an opening therein through which said stud extends, means cooperating with said stud for mounting said cover on said soleplates, a control member for adjusting said switch assembly mounted on said stud, said control member including a cam and a leg extending through said cover, and a control knob rotatably mounted on said stud and engaging said leg for rotating said cam, said switch assembly including a portion engaging said cam whereby rotation of said cam varies the temperature at which said temperature sensing device actuates said switch.

References Cited in the file of this patent UNITED STATES PATENTS 2,274,390 Weeks Feb. 24, 1942 2,582,024 Finlayson Ian. 8, 1952 FOREIGN PATENTS 539,666 Great Britain Sept. 19, 1941 671,069 Great Britain Apr. 30, 1952 

